O2 Sensor Pumping Current Circuit Low (Bank 2 Sensor 1)
The pumping-current line of the wide-band oxygen sensor on bank 2, sensor 1 is below the lower threshold. Wide-band sensors use a small pumping current to keep their measuring cell at lambda 1; a low value usually means an open or shorted pump cell.
Affected components
- Oxygen sensor upstream b2
- Oxygen sensor wiring
Common causes
- High likelihood: Pump cell open or sensor failed
- Medium likelihood: Pumping current line shorted to ground
- Low likelihood: Connector pins corroded - high contact resistance
Possible symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.